Fuel Tank Pressure Sensor, code PO453

Tiny
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Hi,

I went through the entire powertrain management schematic and found no 5-pin connector with yellow/orange wires. Additionally, I can find all junction connectors but not JC4. This has me confused.

Take a look at the schematics below. Note the original was three pages. I had to cut each pic in half to make them readable. I did overlap them. Also, I highlighted every yellow/orange wire I could find.

Take a look and see if that helps in any way.

Take care and let me know.

Joe

See pics below.
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Tuesday, April 26th, 2022 AT 4:50 PM
Tiny
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Here is a 5 pin with yellow and orange wires. I have a set of wiring diagrams for this car. Hope this will help.
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Friday, April 29th, 2022 AT 10:21 PM
Tiny
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After I looked through the power distribution schematic, that isn't the correct one. There should be an 8-pin connector that controls the CCV. The wires to the connector are all white and it is CBGJC3.

See pic below.

Let me know.

Joe
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Saturday, April 30th, 2022 AT 7:12 PM
Tiny
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Okay, there are three connectors next to each other, and I believe there's one with all white wires.
When I'm checking the ohms am I checking the wires or the close valve itself?
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Saturday, April 30th, 2022 AT 7:23 PM
Tiny
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Hi,

I would check the wiring. If I recall, you mentioned it was operating when you used a jumper.

Here is a link you likely don't need but may find helpful:

https://www.2carpros.com/articles/how-to-check-wiring

Let me know what you find.

Joe
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Saturday, April 30th, 2022 AT 8:25 PM
Tiny
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Okay, Mr. Joe, I got my hands on a bidirectional scanner and the valve is closing through the ECM. I tested the valve for ohms and got 22.2 the first time and 23.6 the second time. I'm confused because when I actuate the valve from the scanner the valve is humming. If I put power and ground from the battery, then it just clicks. So why the humming? Now on another note I noticed if I back probe the valve with a test light, when I actuate the valve from the scanner the test light comes on like it should. But when I turn it off the test light stays on just slightly. So that's a short to ground right? I don't think the short is in the valve itself because if I unplug the harness from the valve the light doesn't go out. I ran a temporary wire from the ECM to the valve, but it didn't change anything. So that tells me the short is not in the ground wire coming from the ECM to the valve. So where should I look? Could it be the positive side that is shorted?
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Saturday, May 7th, 2022 AT 8:56 PM
Tiny
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Hi,

If the light is staying on dim, it could be a ground issue that is allowing power to back feed to the light. If you disconnect the PCM, is power lost?

Let me know.

Joe
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Saturday, May 7th, 2022 AT 9:32 PM
Tiny
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Yes, I think so but I'll check again tomorrow. What about the humming, is that right?
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Saturday, May 7th, 2022 AT 9:51 PM
Tiny
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Let me know what you find. As far as the humming, can you tell for certain where it is coming from? When actuated, that shouldn't continue powering the valve. It sounds like that is what is happening.

Let me know.

Joe
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Sunday, May 8th, 2022 AT 7:01 PM
Tiny
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Yes, it's for sure the valve that's humming.
I think I have tracked it down to a shorted driver because if I bench test the valve it works fine. I ran a temporary wire from the PCM to the valve and it didn't fix anything. When I command the valve on the valve and test light both come on and go out when commanded off,
but the light stays on slightly. It doesn't go out when I turn the key off but if I unplug the PCM it goes out so i'm thinking shorted driver. What do you think of my thinking?
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Sunday, May 8th, 2022 AT 10:48 PM
Tiny
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Hi,

It sounds like you may have found the issue. The light shouldn't stay on. Something continues sending power. It could be a short at a connector, so make sure you check when you are disconnecting things.

Let me know how you make out.

Joe
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Monday, May 9th, 2022 AT 5:50 PM
Tiny
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Have verified with the valve commanded off, 12v on the hot side and 3.5 v on the control wire. Bench tested the valve, it works fine. No humming. In the car commanded on it closes but hums. Shorted driver, right?
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Friday, May 13th, 2022 AT 4:14 PM
Tiny
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That is what it sounds like. Something is feeding power constantly to make it hum. Since you indicated a dim light stays on, there must be a short. I went back through thinking there could be a relay sticking but couldn't find anything.

Let me know if you have other questions.

Joe
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Friday, May 13th, 2022 AT 8:04 PM
Tiny
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Thank you, Joe, I'm convinced it's a shorted driver. I have checked the wires and connectors and don't see a problem.
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Saturday, May 14th, 2022 AT 4:25 AM
Tiny
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Hi,

You are very welcome. If you have a chance, let me know if that takes care of the problem for you.

Take care,

Joe
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Saturday, May 14th, 2022 AT 7:45 PM

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